1. Field of the Invention
The present invention relates to an oil supply for an internal combustion engine as recited in the preamble of patent claim 1, as well as to an oil supply for a two-stroke engine as recited in the preamble of claim 12.
2. Description of the Related Art
Such an oil supply is known from DE 42 43 571 A1. According to this document, in an internal combustion engine a piston can execute back-and-forth movement in a cylinder, and oil can be sprayed against the piston via a nozzle. When the piston is situated in the area of its lower dead center, the oil is sprayed from the nozzle against the contact surface of the piston, and is distributed via grooves that run there on the periphery of the piston. When the piston is situated in the area of its upper dead center, the oil can be sprayed from the nozzle against the lower side of the piston, i.e. the piston base, in order to cool it. When there is a low load on the engine, or the engine is still cool, the nozzle does not spray a stream of oil if the nozzle is exposed, i.e., if the piston is not situated directly in front of the nozzle. The base of the piston is cooled by the oil spray only after the engine has warmed up, and this increases when load is placed on the engine.
From EP 0 609 866 A1, it is also known to directly lubricate the piston contact surface with oil during operation of the internal combustion engine.
From DE 100 45 725 A1, a lean lubrication system for a two-stroke engine is known in which the lubricating oil is likewise dispensed only in the area of a contact surface between the piston and the cylinder, the oil being dispensable in the form of an oil aerosol.
From DE 199 27 931 A1, an internal combustion engine is known having a piston made up of a piston base and a piston skirt. On the underside of the piston base, a cooling pan is attached, forming together with the piston a cooling chamber. Via a supply opening, oil can be brought into the cooling chamber, and can be let out again via a draw-off opening. For this purpose, in the lower dead center standing pipes are coupled to the cooling pan. A similar system is known from DE 198 34 138 C1.